In some ways, the brain is similar to a computer, said Deborah Little, director of MRI research in the department of neurology and rehabilitation medicine at UIC and co-author of the study. "You have the CPU and the memory, but they are worthless unless they are connected to each other. The white matter of the brain has the same function as the cables of the computer."
When white matter is damaged, areas of the brain may appear healthy but they are actually "unplugged" and cannot function.
"This study validates that getting smacked in the head is not a good thing, despite the fact that some clinicians still believe a patient can recover fully after a concussion," said Little.
A significant percentage of patients in the study had no self-reported cognitive deficits, yet they did have permanent damage that was apparent to researchers.
TBI has been a long-standing public health problem and a significant source of disability, but the recent increase in veterans returning from war and athletes who have experienced multiple concussions has generated greater public attention to TBI.
"Very often in TBI there are forces being applied to the brain that stress the tracts of white matter -- pulling them, yanking them -- and the white matter becomes damaged," Kraus said.
Patients who have a contusion, or bruising of the brain, can also suffer from subtle and diffuse damage to the white matter. The researchers believe that not only the focal lesion but the damage to the white matter is very important.
In the study, the researchers were also able to determine axonal damage (tearing of the axons that allow one neuron to communicate with another) in white matter versus abnormalities in the myelin (the protective sheath that, if damaged, can disrupt signals between the brain and other parts of the body.) If an axon is severed, the damage generally cannot be repaired.
"We found that the milder inj
|Contact: Sherri McGinnis Gonzlez|
University of Illinois at Chicago